Thumbwheel switch with illuminated indicating structure



Oct. 24, 1967 w, HEN 3,349,211

THUMBWHE'EL SWITCH WITH ILLUMINATED INDICATING STRUCTURE Filed Nov. 10, 1964 INVENTOR.

2 36 E9. .5: w 4424 z/a/w Z2 0 United States Patent Ofiice 3,349,21 l Patented Oct. 24, 1967 3,349,211 THUMBWHEEL SWITCH WITH ILLUMINATED INDICATDJG STRUCTURE Wallace A. Lien, Palos Vertles Estates, Calili, assignor,

by mesne assignments, to 3-D Equipment Co., Inc.,

Pasadena, Calif., a corporation of California Filed Nov. 10, 1964, Ser. No. 410,170 10 Claims. (Cl. 200-167) This invention relates to the illumination of indicator dials such as in rotary wheel counters and in sectional digital switching devices.

An important object of the invention is to provide a novel digital switching unit wherein digits or other indicia of rotary wheels contained within individual casings are illuminated through the medium of light sources within the individual casings.

A further object is to provide for illumination of such switching devices wherein the light source of each switch module is disposed on the plane of the rotary wheel or drum which is to be illuminated so as to limit overall width of the casing or housing containing the wheel or drum.

A still further object is to locate a series of such switches in side-by-side relationship along a common axis within a minimum space and at the same time to dispose the series of such switch modules in viewable position behind a common panel.

A still further object is to provide for illumination of such indicia through the medium of an annular light conductor about each wheel, on the outer face of which conductor appropriate indicia are applied.

A still further object is to provide a relatively narrow switch of the thumbwheel type having light diffusing characters upon a face of an annular light conductor ring, the ring being mounted on a relatively narrow switching Wheel having finger lugs extending beyond the periphery of the ring, and associated with a light source mounted adjacent the ring to one side of the finger lugs in a manner such that light from the source may be reflected within the conductor ring between the inner and outer walls thereof to illuminate the characters without impeding the movement of the finger lugs.

Other objects of the invention and the various features of construction thereof will become apparent to those skilled in the art upon reference to the accompanying drawing and the following specification and claims.

In the drawing:

FIGURE 1 is a perspective view indicating a practical operative assembly of a plurality of modules of a digital switching device illuminated in accordance with this improvement;

FIG. 2 is a vertical transverse section through one of such modules as indicated by the line 22 of FIG. 1;

FIG. 3 is a perspective view of an annular or cylindrical light conductor mounted upon each of the rotary switching or counting wheels in accordance with this invention;

FIG. 4 is a vertical cross-section approximately as indicated by the line 44 of FIG. 2; and

FIG. 5 is a detailed view of a rotary switch which may be used upon each switching wheel.

Having further reference to the drawing, as seen in FIG. 1, a practical digital switching device embodies a plurality of modules each of which includes a casing or housing unit 10. Each module, and the assembly of modules, is generally similar in construction and operation to that described in Wright US. Patent No. 3,089,923 issued May 14, 1963 for Sectional Digital Switch; but the housing structure and switching wheel structure in each module of the present invention is modified to incorporate the novel illuminating arrangement to be described hereinafter. Each unit is arranged along a common axis in side-by-side relationship, the assembly thus produced being completed at each end by a flanged end plate 12. Each unit or casing 10 also includes a top end wall 14, an apertured front wall 15, a bottom end wall 16 and a rear end wall 18. These walls are desirably integrally formed in conjunction with a side wall 20, as best seen in FIG. 4. The opposite side of each unit 10 is conveniently formed by a removable side wall which is in the form of a printed circuit board 22 on which are printed conductive leads 24. For the purpose of viewing the rotary wheel contained in each unit 10, a window 25 is provided in the respective front wall 15 as probably best indicated in FIG. 2.

In the structure illustrated, each module contains a rotary switching wheel 30, having a central hub or body portion 32 which is provided with a radially extending finger flange provided with finger notches 34 that have outwardly projecting curved finger lugs 35 for engagement by the operators finger. integrally and axially projecting from the hub 32 is a cylindrical rim or drum 36 about which an annular ring-shaped light conductor 60 is mounted. Finger lugs 35 extend radially beyond the outer surface, or periphery, of light conductor ring 60, as shown in FIGURES 2 and 4. Digits or other indicia 62 are provided on the outer surface of each light conductor 60. Each wheel is mounted in rotary position as by the means of integral pivot shaft portions 38 which are carried in suitable bearing portions 49 of the sidewall 20 and the circuit board 22.

The circuit boards 22 are fixed in position on their respective housings 10 as by means of screws 42, and the assembled series of units seen in FIG. 1 are bound together through the medium of appropriate through-bolts 44. Since it is desirable that each character selected on a switching wheel be positively presented at the respective window 25, a centering spring 45 is provided which is in general L-shaped with the angle of the L positioned in the rearward lower corner of the housing, its lower ar-m being held in position as by' a stud 46. The outer end of the other arm of the L is offset inward as indicated at 48 to pro vide a centering section which engages adjacent the extremities of adjacent finger lugs 35.

To effect the desired switching action of each wheel 30 as it is rotated, the side of the wheel 30 opposed to the respective circuit board 22, as seen in FIG. 4 has a fingered wiper switch 50 aflixed thereto in opposed relation to the printed leads 24 of the respective circuit board 22. Such a wiper switch 50 is illustrated in FIG. 5.

A significant aspect of the present improvement lies in the annular light conductor 60 shown separately in FIG. 3, and also shown in mounted operative position in FIG. 2. This light conductor 60 as illustrated is a short continuous cylinder or endless ring of light conductive material which normally would be transparent and is fixed upon the rim or drum 36 of each wheel 30. Such a light conductive material constitutes a light piping medium, and is typically composed of synthetic plastic materials, more particularly that one known as Lucite which is a methyl methacrylate resin. Glass, clear fused quartz, and polycarbonates are also suitable.

A particular novelty of this improvement lies in the location and nature of the digits or other indicia 62 applied to the cylindrical light conductor 60 as illustrated in FIG. 3. The construction of these indicia is such as to render them light diffusing so that they may be efiicientlyseen from any angle from the front of the panel on which the switches are mounted. According to one construction, these characters, which may bethe digits 0 to 9 of the decimal system, may be cut from well-known translucent (as distinguished from clear transparent) tape and secured to the outer surface of the light conductor-cylinder 60. In another construction, such light diffusion may be 1 Another significant aspect of the present invention lies in the location of the light source relative to switching wheel 30 and its finger lugs 35. For the purpose of transmitting light to the indicia 62 on the light conductor 60, a suitable source of light is represented in FIG. 2 by an electric lamp 65 carried in a socket 66 which is fitted into the top wall 14 of the casing at a position remote from a window 25. This lamp 65 is located in the same general plane as that of the light conductor 60, as seen in FIGS. 1, 2, and 4, and extends toward the ring 60 at a location between finger lugs 35 and side wall 20, In this manner no added Width of the housing 10 is required to accommodate the lamp 65. As will be seen from FIGURES 2 and 4, lamp 65 extends inwardly to such an extent that it radially overlaps the path traversed by the finger lugs 35;

but since the lamp 65 is positioned alongside the path, the

rotary movement of wheel 30 is unimpeded by lamp 65 even though the lamp is closely adjacentring 60.

With this arrangement some of the light passing from t the filament of the lamp 65ito the outer surface of the light conductor 60 is refracted through such outer surface, as diagrammatically indicated in FIG. 2, and continues onwa'rdly to strike the inner surface of the light conductor 60 whence they are multiply reflected at angles greater than the critical angle of the light conductor material, and thence around the cylindrical conductor 60. The inner surface 65 of the light-conductor ring 60 is spaced from the outer surface 67 of the drum 36 by a narrow gap 69 to minimize loss of light at the inner surface. To this end the side 70 of the light-conductor ring is cemented to the flange of the rotary Wheel.

By these means adequate illumination of the characters 62 is produced throughout the circumference of the conductor 60. As a result, each character 62 being brought into viewable position in the window 25 of the housing 10 is ,well illuminated and clearly visible to the operator in darkness or other low ambient light.

By the arrangement just described, illumination of the light diffusing characters 62 on the outer surface of the light conductor 60 is readily accomplished, and disposi-.

tion of such characters upon such outer surface is easily produced in practical operation with any of the materials or means above indicated. Also, it will be seen from FIG. 4 that the position of the lamp 65 in each instance overlies the light conductor 60 and is disposed to one sidev of the finger lugs 35 so as to be cleared by the latter during rotation, and the overall thickness of the housing 10 is not increased by reason of the lamp 65.

It will be appreciated that variations of the specific structure may be designed by those skilled in this art without departing from the spirit of the invention sought to be protected.

The invention claimed is:

1. In an illuminated counter structure:

a rotatable wheelrhaving an annular rim and a radial a transparent annular light conducting ring attached to said radial flange and positioned in surrounding relation to said rim to transmit light about said ring by reflection between the inner and outer walls of said the inner surface of said ring being spaced from said rim to minimize loss of light of said innersurface of said ring;

light diffusing indicia disposed upon the outer surface of said ring whereby to be illuminated by light reflected within said ring;

and a light source adjacent said ring to direct light into said ring through the outer surface thereof for reflection within said ring to illuminate said indicia.

2. In an illuminated digital switchstructure:

a casing providing therewithin a chamber;

an indicia-carrying switching wheel rotatably mounted in said chamber about an axis;

said wheel having a rim and finger lugs projecting radially beyond said rim at a position axially spaced from a side wall of said casing;

an annular light conductor fixed on said rim at a position between saidfinger lugs and said casing side wall;

light-diffusing indicia carried on a circumferential surface of said conductor; and

a source of light carried within said casing adjacent said conductor at a position between said fingerlugs and said casing side wall and along side the path of movement of said finger lugs to project light into said conductor through the outer surface thereof to illuminate such indicia.

3. A device wherein a plurality of the digital structures of claim 2 are arranged in side-by-side aligned relationship presenting the indicia of said wheels in a series, the I light from each of said sources being confined within its casing by intervening ones of said casing side walls disposed between said aligned structures.

4. An illuminated digital switch comprising:

a plurality of narrow switch supporting structures arranged side by side in aligned relationship;

each of said switch supporting structures including a side wall positioned betweenadjacent ones of said aligned supporting structures,

each of said supporting structures also includingan end wall in alignment With a like end wall in an adjacent one of said supporting structures, said end wall in each supporting structure extending transverse to said side wall of said supporting structure;

a rotary switching wheel mounted on each of said supporting structures, the axes'of the various switching wheels being aligned;

each of said switching wheels including means for selectively completing different ones of a plurality of electrical circuits upon rotation of said wheel;

each switching wheel having a peripheral transparent annular light-conducting ring mounted thereon to transmit light about said ring by reflection between the inner and outer Walls of said light-conducting ring, the inner surface of said ring being out of contact with said switching wheel to minimize loss of light at said inner surface of said ring;

light diffusing indicia disposed upon a surface of each of said light-conducting rings;

means defining an open window for each of said switching wheels through which window a portion of said wheel projects to permit manual rotation of said wheel, and through which window one of said indicia may be viewed to identifythe electrical circuit then being completed by said switching wheel;

and a light source mounted in each of said supporting structures and extending from said end wall to a position adjacent the respective light-conducting ring to project light into said conducting ring through the outer surface thereof: to illuminate the respective indicia, each light source disposed within the thickness of the respective wheel in the general plane thereof;

and thereby illuminating the indicia of each wheel independently of the other wheels.

5. The structure of claim 4 wherein each of said switching wheels includesan annular rim and a radially extending flange at one side of said rim,

said annular ring being positioned in surrounding relation to said annular rim with the inner surface of said ring being spaced by a gap from the outer surface of said rim to elfect said minimization of light loss at said inner surface of said ring,

a side edge of said ring attached to said radially extending flange to hold said ring in said spaced relation to said rim.

6. The structure of claim 5 wherein each of said supporting structures comprises a casing enclosing a chamber in which said switching wheel is mounted,

said light source being mounted in said end wall at a position remote from said window and accessible from the exterior of said casing,

and said light source extending internally of said casing in a direction generally parallel to the side wall of said casing to a position adjacent said switching wheel and annular ring.

7. In combination in a multiple selector switch:

a plurality of multiple-position switches each of which includes an outer wall,

a stationary switch structure, and

a rotary switch structure,

the stationary switch structures rigidly mounted together as a composite stationary unit in side-by-side relation along a common axis,

each of said stationary switch structures having a switch contact board mounted transversely of said common axis, each board having a plurality of stationary switch contacts mounted thereon,

' means for mounting said composite unit behind a switch panel window structure with said common axis parallel to said panel,

each switch unit having an operating wheel mounted for independent rotary movement about said axis parallel to said panel,

a plurality of finger lugs projecting from each operating wheel and spaced apart to provide for receiving the distal portion of an operators finger on either side of a lug adjacent said window,

each operating wheel having a peripheral transparent annular light conducting ring mounted on said wheel alongside said finger lugs to transmit light about said ring by reflection between the inner and outer walls of said light conducting ring;

light diffusing indicia disposed upon a surface of each of light-conducting rings;

and a light source mounted on each of said switches externally of the respective light-conducting ring and at a position remote from said open window to project light into said conducting ring through the outer surface thereof to illuminate the respective indicia, each of said light sources having a support structure extending through said outer wall of its associated switch and being removable from the exterior side of said outer wall, each light source being disposed Within the thickness of the respective wheel in the general plane thereof, and thereby illuminating the indicia of the respective wheel, each light source including a light emitting portion lying alongside the path of movement of the respective finger lugs and closely adjacent to the outer surface of the respective light conducting ring.

8. An illuminated thumbwheel type switch; comprising:

a manually rotatable multiple position thumbwheel;

a housing structure supporting said thumbwheel and including a circuit board having a plurality of electrical connector terminals,

contact means movable with said thumbwheel and cooperating with said circuit board for making electrical connection to different ones of said terminals upon rotation of said thumbwheel from one to another of said multiple positions,

a portion of said thumbwheel extending outwardly of housing structure;

said thumbwheel having a peripheral transparent annular light-conducting ring mounted thereon to transmit light about said ring by reflection between inner and outer walls of said light-conducting ring, substantially the entire inner surface of said ring being out of contact with said thumbwheel to minimize loss of light at said inner surface of said ring;

light diffusing indicia disposed upon an annular surface of said ring; and

a light source supported by said housing structure adjacent said ring at a position remote from the outwardly extending portion of said thumbwheel to project light into said ring through the outer surface thereof to illuminate at least that one of said indicia which is located adjacent the outwardly extending portion of said thumbwheel, said light source being located within the thickness of the wheel and in the general plane thereof.

9. The switch of claim 8 wherein said thumbwheel includes an annular series of operating finger lugs radially extending from said thumbwheel at one side of said lightconducting ring,

said light source lying alongside said lugs in close proximity to said light-conducting ring and to one side of said lugs.

10. The switch of claim 9 wherein said light source is fitted into an apertured wall portion of said housing structure at a position overlying said ring, said light source including support means accessible from the exterior side of said apertured wall portion to permit said light source to be removed from said housing structure without disassembly of said housing structure.

References Cited UNITED STATES PATENTS 1,720,085 7/1929 Meyers 40-68 2,728,155 12/1955 Hunter 4077 3,040,458 6/1962 Mathews 4077 3,089,923 5/1963 Wright 200-167 3,140,377 8/1964 Koci et al. 200-167 3,201,785 8/1965 Knotowicz.

3,222,465 12/1965 Huntress et a1. 200-167 3,222,490 12/ 1965 Huntress et al. 200-167 ROBERT K. SCHAEFER, Primary Examiner.

EUGENE R. CAPOZIO, Examiner.

W. GRIEB, H. O. JONES, Assistant Examiners. 

1. IN AN ILLUMINATED COUNTER STRUCTURE: A ROTATABLE WHEEL HAVING AN ANNULAR RIM AND A RADIAL FLANGE; A TRANSPARENT ANNULAR LIGHT CONDUCTING RING ATTACHED TO SAID RADIAL FLANGE AND POSITIONED IN SURROUNDING RELATION TO SAID RIM TO TRANSMIT LIGHT ABOUT SAID RING BY REFLECTION BETWEEN THE INNER AND OUTER WALLS OF SAID RING; THE INNER SURFACE OF SAID RING BEING SPACED FROM SAID RIM TO MINIMIZE LOSS OF LIGHT OF SAID INNER SURFACE OF SAID RING; LIGHT DIFFUSING INDICIA DISPOSED UPON THE OUTER SURFACE OF SAID RING WHEREBY TO BE ILLUMINATED BY LIGHT REFLECTED WITHIN SAID RING; AND A LIGHT SOURCE ADJACENT SAID RING TO DIRECT LIGHT INTO SAID RING THROUGH THE OUTER SURFACE THEREOF FOR REFLECTION WITHIN SAID RING TO ILLUMINATE SAID INDICIA. 